1. Field of the Invention
This invention relates generally to compositions, methods and apparatus used for the manufacture semiconductor, photovoltaic, LCF-TFT, or flat panel type devices. More specifically, the invention relates to new precursors for deposition of metal films on to substrates.
2. Background of the Invention
As the design and manufacturing of complementary metal-oxide semiconductors (“CMOS”) circuits continues to evolve, the industry is constantly seeking new and novel methods of depositing films onto substrates, such that the resulting film will have certain sought after properties. For example, transition metal thin films may be used as adhesion/seed layers in copper interconnects and as magnetoresistive multilayers in magnetic random access memory devices.
Nickel and cobalt films are desired for future semiconductor devices. In some CMOS architectures NiSi and CoSi2 films may eventually replace the metal gate currently used in conventional transistors. Cobalt silicides may be utilized in device scale-down processes due to their good thermal and chemical stability, low resistivity, wide process window, and the small lattice mismatch to the silicon crystal lattice, which allows the cobalt silicide to be grown epitaxially on the silicon. Furthermore, nickel oxide and cobalt oxide films may be used in the construction of MRAM or FeRAM type devices.
Currently, the main industrial options suitable to deposit such thin films with reasonable throughput and acceptable purity are vapor phase deposition techniques such as chemical vapor deposition (“CVD”) and atomic layer depositions (“ALD”). Both of these techniques for depositing a film on a substrate require the use of precursors which are thermally stable, easily vaporized, reactive, and which cleanly decompose.
Consequently, there exists a need for methods and precursors for depositing films containing late transition metal layers.